Optical brighteners containing sulfonic acid groups of the bis-styrylbenzene series

ABSTRACT

Bis-styrylbenzene compounds having sulfonic acid groups which are useful as optical brighteners, especially for natural and synthetic polyamides and cotton.

United States Patent 1191 Scheuermann et al.

[451 Sept. 9, 1975 OPTICAL BRIGHTENERS CONTAINING SULFONIC ACID GROUPS OF THE BIS-STYRYLBENZENE SERIES [75] Inventors: Horst Scheuermann, Ludwigshafen;

Peter-Matthias Hell, Frankenthal; Gottfried Burkhardt, Ludwigshafen, all of Germany [73] Assignee: Badische Anilin- & Soda-Fabrik Aktiengosellschaft, Ludwigshafen (Rhine), Germany [22] Filed: May 4, 1970 [2]] Appl. No: 34,622

[30] Foreign Application Priority Data May 7, 1969 Germany l923267 [52] US. Cl 260/505 R; 8/1 W; 8/89; 260/61 1 A [51 Int. Cl. C07C 143/24 OTHER PUBLICATIONS Organic Chemistry, Morrison et 211., 2nd ed. 1966), pp. 870, 871.

Primary Examiner-Bernard Helfin Assistant Examiner-A. Siege] Attorney, Agent, or Firm -Johnston, Keil, Thompson & Shurtleff [5 7 ABSTRACT Bis-styrylbenzene compounds having sulfonic acid groups which are useful as optical brighteners, especially for natural and synthetic. polyamides and cotton.

6 Claims, No Drawings OPTICAL BRIGHTENERS CONTAINING SULFONIC ACID GROUPS OF THE BIS-STYRYLBENZENE SERIES The invention relates to new compounds having the general formula (I);

CH=CH CH=CH where A denotes hydrogen, chlorine or methyl;

R denotes hydrogen, chlorine or bromine or alkyl or alkoxy having one to eight carbon atoms;

R denotes hydrogen, chlorine or methyl, methoxy or ethoxy;

R and R" denote hydrogen, chlorine, methyl or methoxy; and

n denotes one of the integers l and 2, at least three substituents other than hydrogen being present in the molecule.

Examples of alkyl groups having one to eight carbon atoms are methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, t-butyl, n-hexyl and n-octyl. Examples of appropriate alkoxy groups are methoxy, ethoxy, butoxy and octoxy.

In one group of compounds having the general formula:

Q CH=CH CH=CH (ao s) (S03E02 which is of particular industrial importance, R and R denote hydrogen or methyl and R denotes hydrogen when n 2 or chlorine, alkyl having one to four carbon atoms or methoxy or ethoxy when n l. The new compounds are colorless to pale yellow substances which are completely soluble in water. They may be used for example in the form of free acids or preferably as alkali metal salts or ammonium salts.

They are outstandingly suitable for the optical brightening of wool, silk, synthetic polyamides such as nylon 6 or nylon 6,6 or compounds having an analogous chemical constitution and particularly cotton. The oustanding degree of whiteness and the brilliance and high color strength which can be achieved ,with the new compounds are to be emphasized. Moreover good light fastness properties are achieved.

For the production of the new compounds, for example a compound having the general formula (II):

where X denotes chlorine, alkyl or alkoxy and Y denotes hydrogen, alkyl or alkoxy, may be sulfonated with concentrated sulfuric acid or oleum.

The new compounds may be prepared more advantageously by sulfonating an aldehyde having the general formula (Ill):

(III) where A, R and R have the meanings given above, with concentrated sulfuric acid or oleum and the reaction products in the form of alkali metal salts are treated in a Wittig reaction (for example according to the process of German Patent No. 1,108,219) with a compound having the general formula (IV):

EXAMPLE 1 54 parts of sodium methylate solution in methanol is slowly added while stirring at 30 to C to a mixture of 38 parts of tetraethyl pxylylenediphosponate, 49 parts of the sodium salt of 4- methylbenzaldehyde-3-sulfonic acid and 250 parts of dimethylformamide. The whole is then heated at to C for 3 hours and stirred overnight at room temperature. The reaction mixture is poured into 1,500 parts of acetone and the precipitate suction filtered and heated at to C in 25 0 parts of 18% aqueous common salt solution while stirring and then cooled to room temperature. The crude product is suction filtered and recrystallized from a mixture (1, 1) of dimethylformamide and water. 35 parts (68% of the theory) of the disodium salt of l,4-bis-(4-methylstyryl)- benzene-3,3"-disulfonic acid is obtained in the form of colorless to pale yellow crystals. Fluorescence spec 3 4 trum: A =425 millimicrons, measured in dimethyland after another 2 hours 45 parts of 2.4% oleum is formamide. The compound has the formula added. The mixture is further stirred for fourand a half CH CH=CH among CH .ngo gf f j SO Na The 'sodiumsalt of 4 methylbenzaldehyde 3-sulfonic hours at 90 to 95C and then cooled to room temperaa'cid required as starting'compound may be prepared as ture. The solution is poured onto 2.000 parts of ice and follows: the product salted out by adding common salt. The

96 parts of p methyIhen Laldehyde is gradually added whole is suction filtered and the crystal pulp issusto 480 parts of 25% oleum while stirring, the temperapended in 600 parts of saturated aqueous common salt turebeing kept below 30C. The solution is stirred for solution and heated at 80 to 100C while stirring. The 3 hours at 80 to 90C, cooled and poured onto 2,000 reaction product is suction filtered at room temperaparts of ice. The reaction product is separated by saltture and dried at subatmosphcric pressure at 50 to ing out with common salt, suction filtered and stirred 60C. 172 parts of sulfonate having a common salt con with 800 parts of saturated common salt solution at 80 tent of 26.5% is obtained. This is equivalent to 66.5 70 to10'0C. After having been cooled to room temperaof the theory. tu're,'-'thc product is suction filtered again and dried undensubatmospheric' pressure at 50 to 60C. 179 I EXAMPLE parts 'of stilfonateis obtained having a contentof com- I mon salt of 29.5%; this is equivalent to. 71% of the the- 76 parts of tetraethyl p-xylylenediphosphonate is disory. solved in 1,000 parts of dimethylformamide and 117 parts of the disodium salt of benza1dehyde-2,4-

EXAMPLE 2 disulfonic acid is added. Then while stirring at to 54 parts of a 30% solution of sodium methylate in C, 180 parts ofa 30% solution of sodium methylate methanol is allowed to flow slowly at 30 to 40C while in methanol is allowed to flow in slowly. The whole is stirring into a mixture of 38 parts of tetraethyl p- 3( heated for 5 hours at 50 to 60C and stirred overnight xylylenediphosphonate, 54 parts of the sodium salt of at room temperature. The mixture is poured into 2,500

4- rnethoxybenzal'dehyde -3-sulfonic acid and 300 parts parts of acetone and the precipitate is suction filtered of dimethylfprmamide. The whole is then stirred for 3 and dissolved in 500 parts of water. A pH of 3' to'4 is hours mp0 to 70C and then overnight at room temset up with sulfuric acid, insoluble matter is suction filp eratur e. The reaction mixture is poured into 1,500 35 tered and 2500 parts of ethanol is added to the filtrate. parts of acetone, the precipitate is suction filtered and The crystal pulp which separates is dissolved hot in 400 stirred with 300 parts'of 18% aqueous common salt at parts of 90% aqueous dimethylformamide. insoluble 80 100C and then cooled to room' temperature. matter is filtered off and isopropanol is added to the fil- The rea c tio'n product is suction filtered and dried at trate. After isolation, 62 parts of the theory) of subatrnospheri'c pressureat to 60C. 46 parts of the 40 the tetrasodium salt of 1,4-bis-styrylbenzenedisodiui n salto'f 1,4-bis (4 methoxystyry1) benzene 3' 2',2",4',4"-tetrasulfonic acid is obtained. Fluores- QY -disuIf nic acidis obtained in the form of a pale yelcence spectrum: A 432 millimicrons; measured in low powder containing21.5% of common salt. This is dimethylformamide. The tetrasodium salt has the forequivalent to 66% of the theory. Fluorescence specmula:

SOQNG. NaO S NaO S .CH on 0 OH on SOaNa trum: k 435 -rnillimicrons, measured in dimethyl- EXAMPLE 4 forrnamide.

- i y T he compound has-the formu1a:-,- As described in Example 1, 42 parts of tetraethyl pxylylenediphosphonate is reacted with parts of the sodium salt of 2-methoxybenzaldehyde-5-su1fonic acid. CH CH 3 The crude product obtained is dissolved in 400 parts of i Y o Na aqueous dimethylformamide with heating and the 3 3 insoluble matter is filtered off. The sulfonate is precipi- The sodium salt of 4-methoxybenzaldehyde-3- tated from the filtrate with isopropanol. 35 parts (58% su1fonic acidiequired as starting compound may-be of the theory) of the disodium salt of 1,4-bis-(2- prepared as follows: I methoxystyryl)-benzene-5,5"-disulfonic acid is ob- ""109 parts of"p-rnethoxybenzaldehyde is-gradually tained in the form of yellow crystals. Fluorescence added to 450 parts of 5% oleum while stirring, the temspectrum: A 438 and 416 millimicrons, measuredperature of the mixture being kept below 10C. The in dimethylformamide. The disodium salt has the forwhole is then heated up within an hour to to C mula:

on3 caso CH CH Q-CH CH NaO S SO Na EXAMPLE EXAMPLE 7 42 parts of tetraethyl p-xylylenediphosphonate is re- 42 parts of tetraethyl p-xylylenediphosphonate is acted with 67 parts of the sodium salt of 2,4- condensed with 61 parts of the sodium salt of 4- dimcthoxybcnzaldchydc-S-sulfonic acid according to chlorobenzaldehyde-2-sulfonic acid as described in Ex- Examplc l. The crude product is dissolved for purificaample l. The crude product is dissolved while heating tion in 600 parts of 70% aqueous dimethylformamide in 400 parts of 80% aqueous dlimethylformamide, insolinsolublc matter is filtered off, and the sulfonate is preuble matter is filtered off and the product is precipicipitatcd with ethanol. 39 parts 59% of the theory) of tated with isopropanol. 36 parts (59% of the theory) of thc disodium salt of l,4-bis-(2,4-dimethoxystyryl)- the disodium salt of l,4-bis'(4-chlorostyryl)benzenenz n -5 ,5"-disulfonic acid is obtained in the form 2,2"-disulfonic acid is obtained in the form of pale yelof luminescent yellow crystals. Fluorescence spectrum: low crystals. Fluorescence spectrum: A 429 milli- 462 millimicrons, measured in dimethylformamide. The disodium salt has the formula microns, measured in dimethylformamide. The disodium salt has the formula:

OCHa CH O o s SO N8.

SO Na N oals EXAMPLE 6 EXAMPLE 8 42 parts of tetraethyl p-xylylcnediphosphonate is 26.5 parts of tetraethyl p-xylylenediphosphonate and condensed with 61 parts of the sodium salt of 2- 37.5 parts of the sodium salt of 2,4- chlorobenzaldehyde-S-sulfonic acid in the manner dedimethylbenzaldehyde-S-sulfonic acid are reacted as scribed in Example I. The crude product is dissolved described in Example 1. The crude product is dissolved for further purification in 300 parts of hot 80% aqueous in 400 parts of dimethylformamide while heating and dimethylformamide and insoluble matter is filtered off. insoluble matter is filtered off. After precipitation with After precipitation with isopropanol, 28 parts (46% of acetone, 23 parts (61% of the theory) of the disodium the theory) of the disodium salt of l,4-bis-(2- salt of l,4-bis-(2,4-dimetlhylstyryl)-benzene-5,5"-

chlor0styryl)-benzene-5;5-disulfonic acid is obtained disulfonic acid is obtained in the form of yellow crysas a yellow powder. Fluorescence spectrum. )t,,,,, ,=445 tals. Fluorescence spectrum: k 432 millimicrons, and 434 millimicrons, measured in dimethylformmeasured in dimethylformamide. The disodium salt has amide. The disodium salt has the formula: the formula:

C1 v C1 NaO S I sOaNa CH3 H3O H30 CH on G CH on on NaO S C s EXAMPLE 9 t or; aw CH naoa's H3 i i EXAMPLE 10 The 42 parts of p-xylylenediphosphonate in Example 6 is replaced by 485 parts of 2,5-dimethoxy-pxylylenediphosphonate and analogous processing is carried out. 30.5 parts (45% of the theory) of the disodium salt of l,4-bis-( 2- chlorostyryl )-2,5- dimethoxybenzene-S,5f-disulfonic acid is obtained as a yellow powder. Fluorescence spectrum: A 460 millimicrons, measured in dimethylformamide. The disodium-salt has theilfor-mula:

v,L2,5 dirnethozgy-p-ggylylepe-diphosplionate and analogous pr oeessing is carried'out 74 parts (49% of the the- .1 ory) of the ltetrasodi u m' Sago? l,4 -'bis-styryl-2,5- dimethoxybe niene-2Q2 ',4',4 -teti'asulfonic acid is -obtained as a yellow powder. Fluorescence spectrum:

A 475 and 450 millimicrons, measured in dimethylformamide.

compound s charaeteriged by their sljbsti tuents in the following Table and having the general formula:

Q- B} B 13 may be prepared in an analogous manner.

M in the Table denotes hydrogen or an alkali metal atom such as sodium (Na) as in the preceding exampies. I

is alkyl of l to 4 carbon atoms or chlorine; R is hydrogen or methyl; and R is hydrogen, chlorine or methyl 2. An optical brightener as claimed in claim 1 of the formula ll R4 cn=c J CH=CH W H.035 IB wherein: 5. The compound of the formula R has the same meaning as claim 1; and R is hydrogen or methyl. m 3. The compound of the formula 53C CH=CH CH=CH NaO S H C 4. The compound of the formula 6. The compound of the formula on H. c

5 5 H3C CH=CH H ccn=cnon=cn cm NaO S Cl NaO 3 SO Na SO Na =0 0 CH HQ H N SO a 

1. AN OPTICAL BRIGHTENER OF THE FORMULA
 2. An optical brightener as claimed in claim 1 of the formula
 3. The compound of the formula
 4. The compound of the formula
 5. The compound of the formula
 6. The compound of the formula 